Solve for n

Question

á = (n-2) * 180 / n = 180 – 360/n

Answer 1

Although you do not need to know this to answer that question, that is the formula for each internal angle (a) of a regular polygon with n sides.

360/n = 180-a

n = 360/(180-a)

n = 4 for a = 90 degrees (a square) etc.